Cisco has released security updates for an actively exploited zero-day vulnerability, CVE-2026-20316, affecting Cisco Secure FMC (Secure Firewall Management Center) software. The flaw, disclosed on July 29, 2026, allows a remote, unauthenticated attacker to log in to vulnerable systems using a built-in low-privilege account and access sensitive data. 

Cisco said it detected active exploitation in July and has published indicators of compromise (IoCs) to help organizations identify potential attacks. The vulnerability was reported by Jimi Sebree of Horizon3.ai. 
Static credentials expose Cisco Secure FMC systems 

Cisco describes CVE-2026-20316 as a static credential vulnerability (CWE-2...